The rediscovery of Aphanoascus cinnabarinus

January 1973

Journ. Jap. Bot. Vol. 48 No. 1

21

Shun-ichi Udagawa* & Masaki Takada**: The rediscovery
of Aphanoascus cinnabarinus

: Aphanoascus cinnabarinus

In 1889 an unknown cleistothecial Ascomycete was isolated from alligator
excrements in Austria, from where it was subsequently described by Zukal
(1890)®^ as Aphanoascus cinnabarinus, n. gen., n. sp. The genus has remained
monotypic and, so far as we are aware, unreported since it was originally
'described. Recently our attention has been called to this subject, because
Apinis (1968)^^ pointed out the similarities of Anixiopsis stcrcoraria (Hansen)
Hansen to Aphanoascus cinnabarinus. He stated: “there is no doubt that the
present name of isolates of Anixiopsis stercoraria (Hansen) Hansen in fact
represent A. cinnabarinus —Zukal’s (1890) generic name has priority against
Hansen’s (1897) but Cooke’s (1875) specific epithet*** has the priority against
the other two species names proposed by Hansen and Zukal—therefore, the
correct name for this fungus is Aphanoascus fulvescens (Cooke) comb, nov.”
His treatment was followed by Malloch and Cain (1971)®^, although they
assigned the genus to a member of the Onygenaceae. On the basis of his
observation on new material agreeing in every respect with Zukal’s descrip¬
tion of A. cinnabarinus, however, de Vries (1969)®' redefined Anixiopsis
Hansen and regarded the genus Aphanoascus as unrelated. Unfortunately
Apinis himself stated that “so far it has not been possible to locate Zukal’s
type specimen”, so that his conclusion of this species was apparently not
based on the type material.

In the course of a mycological survey on the Japanese soils, the authors
frequently encountered a species of beautiful, reddish orange fungus belong¬
ing to the cleistothecial Ascomycetes. This species was collected from
different localities of Japan in 1967-1968. It has also been collected from
tropical soil, Lae, Morobe Dist., Papua and New Guinea. When grown on

■" Department of Microbiology, National Institute of Hygienic Sciences, Kamiyoga 1-chome,
Setagaya-ku, Tokyo 158.

** Research Laboratories, Toyo Jozo Co., Ltd., Ohito-machi, Shizuoka-ken 410-23.

*** Badhamia fulvescens Cooke in Grevillea 4; 9, 1875.

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Fig. 1. Aphanoascus cinnabarinus. a. Cleistothecium. b. Various stages of asci.
c. Ascospores. d. Ascocarp initial.

January 1973

Journ. Jap. Bot. Vol. 48 No. 1

23

oat-meal agar at 25°C, these cultures appear to represent A. cinnabarinus
Zukal in most respects. For a comparative study, living culture of A. cin¬
nabarinus kept at the Centraalbureau voor Schimmelcultures was obtained
through the courtesy of Dr. J. A. von Arx This culture (CBS No. 424.69),
according to the list (1970)^^ was isolated by E. Harri. However, an attempt
to compare it with our isolates was unsuccessful since no cleistothecium has
been observed on the CBS culture. In view of Apinis’ misinterpreted knowl¬
edge on the genus Aphanoascus, it seems appropriate to review the fungus
on the basis of the additional informations provided by these collections.
Description from our observations of the collections is as follows;

Aphanoascus cinnabarinus Zukal in Ber. Deutsch. Bot. Ges. 8 : 296 (1890).
(Figs. 1 & 2).

Colonies on oat-meal agar growing rapidly, plane, consisting of a thin-
mycelial felt in which scattered cleistothecia are embedded, surface appear¬
ing slightly flocculent, light orange to reddish orange, conidial structures,
not produced; reverse pale reddish orange to dark brown.

Cleistothecia superficial, yellowish orange to orange red, subspherical to-
ovate, with base often slightly flattened to hemispherical, 350-600 fx in di¬
ameter, later confluent in small groups, attaining up to 1 mm or more in di¬
ameters, smooth, loosely invested with reddish orange pigmented hyphae.
Peridium membranaceous, pseudoparenchymatous to sclerotioid, 12-20 jj. thick,,
outer part yellowish brown to
reddish brown, consisting of
several layers of hyphal
strands, inner part hyaline,
consisting of sclerotioid masses
of thick-walled, isodiametric
cells measuring 8-16 x 6-14 fx.

Ascus formation slow out¬
wards from the centre in 4-5
weeks or more; at maturity
the inner tissue of cleistothe¬
cium completely disorganized.

Asci irregularly disposed, 8-
spored, hyaline, borne as

Fig. 2. Aphanoascus cinnabarinus. Scanning
electron micrograph of ascospores (scale: 5/i).

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_24_ mmmmm m as m mi ^ mn 48 i

lateral branches from ascogenous hyphae, in short chains, globose to sub-
globose, 9.5-11^ in diameter, evanescent. Ascospores hyaline to pale yellow,
at maturity reddish-colored, broadly elliptical, 4-5.5(-6) x 3-3.5becoming
more or less thick-walled in age, ornamented by irregular, often anastomosing
ridges; ridges longitudinal to oblique or even transverse, 0.5-0.8/4 thick.
Mycelium hyaline to pale yellowish orange, branched, 1-3^ in diameter,
septate, encrusted with pigmented granules, often aggregated into bundles.
Conidial state unknown.

On potato-carrot agar essentially as on oat-meal but growing somewhat
more slowly, usually developing cleistothecia fairly abundantly, in somewhat
deeper shades near dark red.

On malt agar spreading, orange to reddish orange, more or less fioccose,
ripening process of cleistothecia extremely delayed; colony reverse dark
green to dark blue-green with surrounding agar similarly colored.

At 37°C, grows slower than at 25°C, with production of fructification
much reduced and immatured.

The above description of A. cinnabarinus is based upon the cultures
NHL 2673, isolated from pepper field soil, Minamikushiyama-mura, Minami-
takagi-gun, Nagasaki-ken, Sept. 1, 1967, and NHL 2674, isolated from burned
forest soil, Ohito-machi, Tagata-gun, Shizuoka-ken, Apr. 17, 1968. Since none
of ZukaPs specimens of A. cinnabarinus exist, isolate NHL 2673 is designated
;as the neotype. Dried specimen and slides of this isolate are kept at the
National Institute of Hygienic Sciences, Tokyo. Pure cultures of the above
isolates are also deposited both at the Institute for Fermentation, Osaka and
the Centraalbureau voor Schimmelcultures, Baarn. An additional culture of
A. cinnabarinus, NHL 2675, was also isolated from paddy-field soil, Shuzenji-
machi, Tagata-gun, Shizuoka-ken, Sept. 18, 1968. The latest Japanese isolate
agrees in essential morphological characters with the above description, but
differs in having somewhat smaller ascospores (3-4 x 2-3^). One culture
from New Guinea was of special interest, because it produced much larger
ascospores. It may be regarded as new and a full treatment will be pub¬
lished later. Further additional strains representing this species have been
repeatedly encountered among the fungi isolated from soils in temperate
and tropical areas of the Pacific.

Morphologically, the Japanese fungus agrees closely in most respects

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January 1973 Journ. Jap. Bot. Vol. 48 No. 1 25

with the original description and illustration by Zukal, although no conidial
structures were found in our isolates on the common media. Zukal described
its conidial state as “Bo^ryiis-artigen Conidientrager” suggestive of arthro-
aleuriospores type. Whether or not the conidial state was actually associated
with Zukal’s A. cinnabarinus may be still open to speculation but it is be¬
lieved that our isolates represent A. cinnabarinus.

Aphanoascus is characterized by the production of its spherical, cinnabar,
uon-ostiolate ascocarps, which are surrounded by loose wefts of encrusted
hyphae and have a sclerotioid inner tissue, irregularly disposed globose asci,
and ellipsoid-globose and hyaline to reddish orange ascospores ornamented
with several narrow ridges. Usually the cells of sclerotioid inner tissue are
very slowly disorganized from the centre of ascocarp and converted into
asci. The asci may be borne in short chains. This pattern of ascus for¬
mation is strongly suggestive of those seen in most members of the genera
Eupenicilltum (Scott, 1968)®^ and Hemicarpenteles (Udagawa and Takada,
1971)®\ The absence of conidial structures in our isolates as well as the
■colony pigmentation and the morphology of ascocarp initials would separate
the fungus from the latter two genera.

As suggested by von Arx (personal communication), Aphanoascus may
also be related to a thermophilic genus Thermoascus Miehe (Stolk, 1965)
The general appearance of ascocarps, especially in respect of their reddish
orange pigmentation, and the morphology of ascospores are quite similar in
these two genera. However, it is separated from Thermoascus by the pro¬
duction of catenulate asci and irregularly ornamented ascospores, and the
growth behavior at high temperature.

Finally, as already mentioned by de Vries (1969)this fungus is entirely
distinct from Anixiopsis Hansen (1897)^\ The latter is clearly distinguished
by smaller, brownish, thin-walled ascocarps, early developing asci, and more
regularly ornamented ascospores.

Because of the close affinity to Thermoascus and EupenicilHum (or Hemi¬
carpenteles), the genus Aphanoascus is apparently classified under the family
Eurotiaceae.

We are indebted to Dr. J. A. von Arx and the staffs of the Centraal-
bureau voor Schimmelcultures for helpful suggestions.

-25 —

26

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Summary

On the basis of our observation on cultures isolated recently from soil
collections in Japan, a cleistothecial ascomycete Aphanoascus cinnabarinus
Zukal is redescribed and illustrated. These collections appear to be the only
extant representatives of the species. Taxonomical relationship of the genus
is also discussed. Aphanoascus is separated definitely from Anixiopsis by
characters of ascocarps, ascus development and ascospores.

References

1) Apinis, A. E. 1968. Mycopathol. et Mycol. Appl. 35 : 97-104. 2) Centraal-

bureau voor Schimmelcultures. 1970. List of cultures. Supplement 1 to the
27th edition (1968). 39 p. 3) De Vries, G. A. 1969. Mykosen 12: 111-122.
4) Hansen, E. C. 1897. Bot. Zeit. 55: 127-131. 5) Malloch, D. & R. F.

Cain. 1971. Can. J. Bot. 49: 839-846. 6) Scott, B. De 1968. The genus.

Eupenicillium Ludwing. CSIR, Pretoria, S. Africa, 150 p. 7) Stolk, A. C.
1965. Antonie van Leeuwenhoek 31 : 262-276. 8) Udagawa, S. & M.,

Takada. 1971. Bull. Nat. Sci. Mus. Tokyo 14 : 501-515. 9) Zukal, H. 1890..

Ber. Deutsch. Bot. Ges. 8: 295-303.

* * * *

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- 26